An Assessment of Clinical Continuous Glucose Monitoring Targets for Older and High-Risk People Living with Type 1 Diabetes
David N. O’Neal, Ohad Cohen, Sara Vogrin, Robert A. Vigersky, Alicia J. Jenkins, Sybil A. McAuley, Melissa H. Lee, Barbora Paldus, Catriona M. Sims, Richard J. MacIsaac, Glenn M. Ward, Peter G. Colman, Neale Cohen, Leon A. Bach, Kavita Kumareswaran, Stephen Stranks, Morton G. Burt, D. Jane Holmes–Walker, Roland W. McCallum, Joey Kaye, Jane Speight, Christel Hendrieckx, Jennifer A. Halliday, Sienna Russell‐Green, Steven Trawley, Andrzej S. Januszewski, Anthony Keech, Vijaya Sundararajan, Hanafi Mohammed Husin, Philip Clarke, Timothy W. Jones, Elizabeth A. Davis, Martin de Bock, Mary B. Abraham, Geoffrey Ambler, Fergus Cameron, Jan Fairchild, Bruce R. King
Abstract
Aim: To assess relationships between continuous glucose monitoring (CGM) time in range (TIR), 70–180 mg/dL, time below range (TBR), <70 mg/dL, time above range (TAR), >180 mg/dL, and glucose coefficient of variation (CV) in relation to currently recommended clinical CGM targets for older people, which recommend reduced TIR and TBR targets relative to the general type 1 diabetes population. Methods: We conducted a post hoc analysis using the JDRF Australia Adult Hybrid Closed Loop trial database examining correlations in 120 adults with type 1 diabetes of 3 weeks masked CGM (Guardian Sensor 3; Medtronic) metrics ( n = 61 on multiple daily injections, 59 on non-CGM augmented pumps) using manual insulin dosing at baseline and at 26-weeks, with 50% randomized to automated insulin dosing (AID). Results: Correlations between baseline TIR and TAR were strong ( r = −0.966; P < 0.0001), weak for TBR ( r = 0.363; P < 0.0001), and glucose CV ( r = 0.037; P = 0.687) while moderate between CV and TBR ( r = 0.726; P < 0.0001). Associations were similar for participants aged >60 years ( n = 15) versus younger subjects. Correlations of changes in (Δ) TIR with ΔTAR over 26 weeks were strong ( r = −0.945; P < 0.001) and correlations for ΔTBR were weak ( r = 0.025; P = 0.802). ΔCV did not significantly correlate with ΔTAR ( r = −0.064; P = 0.526) but did with ΔTBR ( r = 0.770; P = <0.001). Conclusions: Changes in TIR are not associated with changes in TBR. Thus, we recommend that for older AID users whilst TBR targets should be prioritized to reduce hypoglycemia-related risk, TBR should be addressed independently of TIR. Clinical Trial Registratrion number: (ACTRN12617000520336).